Hey Sweethearts,
I'm on a flight with great wifi access and I find it an excellent opportunity to share my thoughts.
I wanted to raise attention to the importance of split testing ad copies in general!
A couple of days ago I was talking to my native English speaker friend and I asked if he could take a look at my ad copy because I kinda had the feeling that there's room to improve on my ads. Don't get me wrong, I made constant 100% roi with my campaign!
I do speak English very well, but still when it comes to copywriting, it's just another world! My grammar was perfect on the ad copy but my friend could tell it's not written by a native speaker. So he helped me tweaking the text and I had version A (my ad copy) and version B (native speaker's ad copy).
I was really excited to see results, so I have submitted two separate ad groups with the same image, same targeting, same landing page with only the difference in the ad copy (version A and B).
At first it seemed like my “poor English” ad copy did better, but when I started to get more and more traffic it proved me wrong!
So here are the results and you be the judge of how important it is to split test your ad copy:
Version A did 17 conversions at a budget of $350 making back $680 --> ROI: 94%
Version B did 33 conversions at a budget of $350 making back: $1320 → ROI: 277%
Difference? HUGE!! I was leaving money on the table!!
Advice: Always always split test! Even when you know the campaign is converting well. Also don't hesitate to ask your native speaker friend to help you out OR simply just hire a professional! http://onehourtranslation.com of http://fiverr.com is a great source to start out.
Now get back and hustle!! January is coming – the most beautiful part of the year 
XOXO
fbqueen
Great advice. I was actually thinking about posting something similar to this earlier.
A while back I threw up a pretty rushed campaign in France and quickly made some translations using Google Translate.
One of them read something along the lines of, "Télécharger Wallpapers de Chat" or "Télécharger fonds d'écran de chat."
I was intending to say they could download wallpapers for their chat applications, as my traffic source wouldn't allow me to say Whatsapp. But if you understand French you'd know that chat = cat. Perhaps if I had some cat pictures on my landing page it would have converted better. But just goes to show that getting a native speaker to translate the copy for you can help a lot, and in many occasions prevent you from making a blunder like this one.